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I'm totally new to spas. This is our first one and I knew nothing about the technical side of spas. Did alot of internet reading because of the cold water, and learned a little. The jumper was already there. I also wondered why someone would jump this safety feature. Probably because the old (and new) heater had no connector to connect to the main board. The only thing I did was replace the heater.

I just measured the new heater and it is ok.

The "Lim end Heater on" leds or on. Which should mean that there is no safety or temp reason not to power the heater.. But still there is no power to the heater terminals?!

I just read this;

"My 220 Volt Spa No Longer Gets Hot

When calling for heat, is the heat indicator light/icon on on the topside control?

Yes, It Is: Measure the voltage across both hot wires coming from the house. You should see 220 volts on your volt meter - note that measuring from each wire to ground will not give an accurate reading). If you DON'T have 220 volts, then you have an issue with the GFCI breaker in the main breaker box. If you DO have 220 volts across both hot wires coming from the house, then next measure the voltage across both heating element pins. You should see 220 volts. If you do not, then the circuit board is faulty and will need to be replaced or sent to us for repair"

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>> Probably because the old (and new) heater had no connector to connect to the main board.

There are two holes on the top edge of the heater. One is for a high limit sensor and the other is for the thermostat, and they should lead to the circuit board. If the hi limit is bad, the previous owner must have disconnected it and jumpered the connection on the board. Not a great idea, especially if the circ pump dies, the heater burns up and catches the interior of the spa on fire, or just melts a bunch of stuff and causes a lot of damage. Also, if you're in the tub and the heater continues heating beyond it's normal safe temperature and burns you, although that's probably much less likely.

>>> If you DO have 220 volts across both hot wires coming from the house, then next measure the voltage across both heating element pins. You should see 220 volts. If you do not, then the circuit board is faulty and will need to be replaced or sent to us for repair"

That may be an oversimplification. In the USA, you get 220 volts because there are two 110V legs, one comes to each terminal of the heater. If you're not getting 220V, what are you getting? If you're getting 110V, then one of those legs is not getting power, which could be due to a hi limit sensor, flow switch, or the circuit board not calling for heat.

I only see three wires going to your spa, in a 220V installation in the USA, I'd expect at least four. I'm not familiar with how things are wired in Europe, so I'd better leave any discussion on that to an electrician.

Yours heater relay board is a 17 year old board, the newer replacement boards in the USA have the relay's on the front. It's a very easy board to remove and inspect the back to see if any of the relay's are burned. Remove the aluminum rack around it and there are mounting screws in the corners of the board. The ground screw is also a mounting screw.

The heater relay is a common breakdown item for Watkins control packs. Just make sure you light up the connector in the upper right properly when you put it back in.

Did I mention to turn off the power before removing to inspect it?

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the two sensors seem ok. I measured resistance and they gave the right figures according to a chart I found. They are connected correctly to the board, and High limit is not jumped. The pressure switch is jumped. It seems that if the green Lim led is lid, the sensor is ok. The red light lid tells us the circuitboard is calling for heat.

In the Netherlands we get 220 (Hot) from the house, and when called for heat, 220 to the heater terminals, So different from the US.This is what I also measured when the spa was working proparly.

I did remove the relay board (and main board). They look great in front and back. Nothing burned. All soldered connections like new. I gave the relays a slight tab, no result.

So...., I ordered a new Relay circuitboard. After everything I've read and measurded I'm pretty sure that's the culprit..

And I do turn off the power with every move I take Dave! Thanks again for your advise. Keep you posted.

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I'm confused - do you have a pressure switch? Most hot tubs expect to see that circuit open when they turn on. Then the tub waits to see it close when the water starts moving. So merely jumping the switch may be an issue. I'm not positive about how an older Watkins circuit board reads the circuit. If you mean the pressure switch connector on the board is jumpered, then remove the jumper, restart the spa, after the circ pump starts, than replace the jumper. That's only to test the spa. Running your hot tub without a pressure switch is a really bad idea.

You may also have a bad pressure switch. It's a far cheaper item to replace then a circuit board. I've never seen a bad heater relay board that didn't have burns or scorching somewhere. I"m not saying it's not your problem, just that it would be the first time I've heard of the board going bad without being visibly damaged.

I just thought of a customer we had last year with a Hot Springs tub. Old heater was bad and we replaced it. After about a month he called and said it wasn't heating. My first question is "are your filters clean" to which he said "yes."

When I got to his house, his filters looked clean, as white as virgin snow. But the filter that sat on the circ pump fitting was full of clear sticky goo (shampoo and/or sunscreen). When I took that filter out, the hot tub started to immediately heat.

So, try your tub with the filter removed, just to make sure that it not only looks clean, but that it's not clogged.

I know you may have tried some of these ideas already, I'm just trying to save you buying an expensive circuit board until you've eliminated the weird stuff I've encountered that will only cost pennies to check.

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he called and said it wasn't heating. My first question is "are your filters clean" to which he said "yes."

When I got to his house, his filters looked clean, as white as virgin snow. But the filter that sat on the circ pump fitting was full of clear sticky goo (shampoo and/or sunscreen). When I took that filter out, the hot tub started to immediately heat.

So, try your tub with the filter removed, just to make sure that it not only looks clean, but that it's not clogged.

I observed similar about a year ago on my '88 CalSpa; low pressure caused pressure switch to do its job, and removing the filter boosted up the pressure where everything worked. Cleaning that filter didn't help, I ordered two new ones online (so I'd always have a new spare) and have had no issues since.

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a pressure switch Dave? I would say so. I assume it must be in the circuitboard somewhere. Replacing a bad pressureswitch instead of the whole board would be a great fix if needed!

I did remove the jumper once, then the "heater on" and "Lim" leds started blinking right away. So I put it back in, but had to restart to get things to "normal". Next time I'll try your method, restart the spa, after the circ pump starts, than replace the jumper.. By the way, the spa worked fine in this setup for months (since we owned it), including the jumper,

Filter is not the issue, I removed it and the heater still wouldn't heat, for days.

We are now waiting for the new relayboard, Really hope that's the solution.. If not, your pressureswitch replacement will be next on my list.

Thanks again for all your ideas. We really appreciate this.

I'll keep you posted.

Greeting from a rainy and windy Holland.

Aad

ps. I would love to attach more pics of the spa/circuitboards. But space on this forum is very limited so I already reached to max. (I do not mean to critisize, don't get me wrong)

You should be able to measure 240V to the heater leads when the HTR ON LED is lit. . The relay board is likely where this problem originates since you've stated you no longer have voltage at the heater leads and the lamp you've connected no longer lights up. Replacing the relay board with Watkins part number 77119 should resolve this issue.

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You should be able to measure 240V to the heater leads when the HTR ON LED is lit. . The relay board is likely where this problem originates since you've stated you no longer have voltage at the heater leads and the lamp you've connected no longer lights up. Replacing the relay board with Watkins part number 77119 should resolve this issue.

I think so too. Heater is ordered and I will tell you guys how things will work when installed.

Sometimes they've been replaced with a clear plastic flow switch. It would be mounted in the 3/4" hose by the circ pump. It looks like there's a white fitting on the input side of your circ pump, but I can't zoom in to the image clearly. That may be your flow switch.

When the circ pump is running, the switch closes, so if you check for continuity on the wires coming out of the switch, you would get continuity when water's flowing and no continuity when water's not flowing.

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ah off course, a flow switch mounted somewhere in the lines/tubes. Well this spa doesn't have one like that. From what I've read the original flow switch was in the heater itself. From there it was connected (electricly) to the main board. Maybe somewhere down the line the original heater was replaced by the trumpet style one, without flow switch inside. Hence the jumper on the main board..

ah off course, a flow switch mounted somewhere in the lines/tubes. Well this spa doesn't have one like that. From what I've read the original flow switch was in the heater itself. From there it was connected (electricly) to the main board. Maybe somewhere down the line the original heater was replaced by the trumpet style one, without flow switch inside. Hence the jumper on the main board..

You are correct Aad, your spa does not use the flow switch in the link ScubaDave has provided, those were used in 1995 and 1996 only.. The original heater had a built in pressure switch with a cord that connected directly on the circuit board at the location labeled "pressure switch".

The newer style replacement heaters p/n 73792 do not have a pressure switch cord. This heater requires a jumper p/n 72768 on the circuit board where it's labeled "Pressure Switch". Your spa appears to have been fitted with this newer style heater and jumper.

If you don't have a pressure or flow switch, do you have another way to protect the heater from overheating if the circ pump dies? From my experience with some of your competitors, a hi limit switch isn't quick enough.

ScubaDave 6KW heater p/n 73790 & 4KW heater p/n 73791 are the 60Hz versions of the heater you'll see on the newer domestic Hot Spring Spas. These are often sold as a retro fit replacement part for older heaters with a pressure switch. These heaters are often referred to as "PDR heaters" due to the power down reset procedure used to reset it after an overload.

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Ok it seems like the problem is solved. The spa is still hot and "ready" after a couple of days now. So the old relayboard was the problem after all. Even though it looked good, no damage or burn spots, it was not working right.